In recent years, with the popularity of small electronic devices having an image capturing function, such as digital still cameras and digital camcorders, the image capturing functions have been significantly advanced.
For example, such an image capturing device generally has a display such as a liquid crystal display (LCD), and thereby a user can take pictures of an object, confirming resulting to-be-recorded video on the display.
In addition, among digital still cameras, there is an image capturing device capable of, when a shutter is being pressed halfway, (i) setting, as a region of an object (hereinafter, referred to also as an “object region”), a rectangle having a predetermined size measured using center coordinates on a display as a center, (ii) extracting features of the object from the object region, (iii) matching the firstly extracted features with an input image that is inputted after an input image from which the firstly extracted features are extracted, (iv) tracking the object, and (v) adjusting an auto focus (AF) function, an auto exposure (AE) function, and the like.
A conventional technology is that a user sets a rectangular region or an elliptic region including an entire object by a manual operation using a mouse, a touch pen, or the like, then color components for a background are estimated from the set region, then the color components for the background are removed from the set region to determine color components for the object, and eventually the object is extracted (see Patent Reference 1, for example). FIG. 19 is a block diagram of the conventional technology disclosed in Patent Reference 1. It should be noted that a conventional object tracking device 1600 (see FIG. 19) includes a function unit 1611, a function unit 1612, and function units 1601 to 1606. The characters assigned to each of the function units in FIG. 19 indicate processing performed by the corresponding function unit.